Improvement in disintegrating fibrous materials for paper-pulp



Cdaited rabes @sind (titille.-

Aueusr HERMANN FRANZ DnrNrNcn-R, `or BERLIN, rRUssrA.

Letters Patentdio. 108,241, dated October 11, 1870.

IMPROVEMENT IN DISINTEGRATING FlBROUS MATERIALS FOR PAPER-PULP, &c.

The 4Schedule referred te in these Letters Patent and making part ofthe same.

To all whom it may concern: .Y

Be it known that I, AUGUST HERMANN FRANZ DnrNrNenR', of Berlin, in the Kingdom of Prussia, have invented a new Aand useful Improvement in Disintegratiug Fibrous Materials; and I-do hereby declare the following to be a full, clear, and exact description thereof, which will enable those skilled in the art to make and use the same, reference being had to the accompanying drawing formngpart of this specification, in which drawing- Figure l represents a vertical section ot' the apparatus used in carrying out this invention.

Figure 2 is a horizontal section of the same.

Similar letters indicate corresponding parts.

This invention consists in exposing fibrous materials, such as wood or any vegetable substance, to the action of an alkaline solution under superatmospheric pressure, (about sixty pounds to the square ineh,) and at a temperature not exceeding 212o Fahrenheit, in such a manner that, by the combined action of the pressure andthe heat, the fibrous material is split and disintegrated without destroying the fibers by overheating or by the chemicals, the formation of steam in'the interior ot' the disintegrating-vat being prevented, and the alkaline solution used being weak,

and not in any way injurious to the fibers.

The apparatus which I use in carrying out this process 'consists in a vat, which can be hermetically closed, and which is provided with a false perforated bottom, nnderrwhich is situated a perforated coil, which connects with a steam-generator.

A check-valve prevents the contents of the disintegrating-vat from being forced into the steam-generator, and a thermometer, a pressure-gauge, and suitable try-eocks in the side and on the top of said vat enable the operator to regulate the operation, and, particularly, to insure the proper filling up of the vat, and to control the temperature of the same.

In the 'drawingq The letter A designates a vat, made of sheet metal, or of any'other suitable material, of sutlicient strength to contain, without danger, au internal pressure of sixty pounds to the 'square inch.

Said vat is provided on top with a cover, a, which can be screwed down air-tight, and it is also furnished with au aperture, l), near its bottom, which can be closed air-tight by a suitable plate, and which serves to withdraw the contents of the vat. p

Said vat' is provided with a falscperforated bot-tom, c, `and under this bottom is situated a perforated coil,

ll, which eonnects,vby a pipe, e, with a steam-generator.v

A check-valve, f, prevents the contents of the vat from being forced into the steam-generator.

In thesides of the vat are, two gauge-cocks, g l1, for the purpose of controlling, with the aid of the thermometer and pressure-gauge, the temperature, and

also the pressure of the liquid in the vat, and in the top of said vat is secured a try-cock, fi, for the pur pose of allowing an escape of the air contained in the vat, and also to observe if thevat is properly filled, and if any steam has been formed inV the interior of said vat.-

A thermometer, j, serves to regulate the temperature, and a pressnrefgauge, k, allows of controlling the pressure in the interior of the vat.

Said vat connects at its top, by a pipe, l, with a tank, B, and it is provided with a faucet, m, below its false bottom, to draw off the liquid contained therein.

' Suitable pipes, u o, earrythe liquid, drawn off by either of the cocks, down into the leceivingtank G.

In applying my process to straw or other fibrous material, for the purpose of producing paper-pulp, I proceed as follows:

Int-he tank B, I form a solution of soda, in water, of about 1o Baume, and heat the' same to about 1750. 'lhe straw or other fibrous material, without requiring any cleaning or asserting, is out up into pieces `about one-fourth to ouehalf inch'long, and then introduced into the.disiutegrating-vat. The pipe l is opened, and the raw material is steeped with lye. In a short time, the raw material absorbs a quantity of the lye, and it sinks down in theta-nk, thesurpluslye is drawn off, a fresh supply of raw material is intro- Aduced and steeped ywith lye, and this operation is repeated until thevat A is filled with steeped raw material up to its mouth. (My experienccshows that it requires about one pound of soda to ten pounds of raw material.) After it is found, by opening the cock e', that all the air has been driven 'out of the vat, the pi pe c is opened, and steam is admitted until the presse ure in the vat reaches about sixty pounds to the square inch. By the action of the steam, the temperature of thevcontents of the vat-is raised from 175 to about 2100, and the vat is kept at this temperature, and under the above-named pressure, for from four to six hours, care being takenthat no steam shall form in the interior of.the disintegrating-vat, and that the temperature shall remain as near as .possible at a uniform point, which is easily eiected by means of the thermometer and by the cocks g and h.

By the combined action of the heat and pressure, the silicio acid, the chlorophyh'and a portion of the gelatine are dissolved, and the horny scale, the mar rowrays, and the knot-s of the raw material are ,softened and split by a very weak alkaline solution, while the cellular. texture remains intact, whereas, in the VVarious processes heretofore used ibrdisintegrating brous materials, strong lyes and high temperatures are considered essential, and thereby the texture of the fibers is destroyed, and the fibers are charred and browned.

When treated according to my process, the fiber obtained is nearly white, and can be readily bleached and used for the manufacture of paper. This purpose I etect by removing the fibrous material from ythe disintegrating-vat, and exposing it to a Washing process in a suitable drum. During this process, the fibers are separated, and, after havingr been washed,

they can readily be redueedto pulp with comparatively little expenditure of power. The yield of pulp is about ninety per cent. of the raw material. l l

For the purpose of bleaching, the. pulp is spread upon a oor tothe dept-h of' from saine adheres to the fibers, and renders the bleaching process exceedingly diiicult.

- 'By the addition of soda, as above stated, I obtain a solution of hypochlorite of soda, which is brought 'in contact with the'pnlp, the action oi' thc liquid being facilitated by imparting to the mass a revolving mot-ion in a suitable drum, and by admitting a sutli-r cient quantity of steam to raise the temperature' to about 96. By the heat,l the pulp remains soft, the bleaching action becomes uniform, and the bleaching.

liquid is completely spent.l

The yield ot' bleached pulp is from seventy-five to eighty per cent, of the raw material,

My process can also be used with advantage for producing fibers capable of being spun from-various two to three feet, Aand moistened with diluted sulphuric' acid of about o plants, such as nettles, thistles, broom-corn, rhamie, and so forth. The process in this case is substantially the same as above stated. The stalks of the plants are cut up into pieces-ot' suitable length, (say three or four inehes,) and steeped in the disintegratng-vat with an alkaline solution of 2 Baume. After the disintegrating-vat has been filled with the steeped raw material, steam is admitted, and a pressure of sixty V pounds to the square inch is 4maintained in said vat for about eight hours, care being taken to keep the temperature uniformly at from 210 to 212;

In treating plants where the wood ber appears conjointly with the bast fiber, such, for instance, as broom-corn, the strength of th`e alkaline solution has to be increased to 3o Baume, and the steeped material has to be kept in the disintegrating-vat under pressure for twelve hours, so as to separate the wood fiber from'the bast ber.

The ber obtained by my process from u-rticaceous and papilionaceous is superior in durability to cotton, and, after having been bleached, they assume a more brilliant white color than cotton, being equal in every respect to linen' or hemp;

What I claim as new,l and Letters Patent, is

1. The within-described process of disintegratiug vegetable vfibrous material, by subjecting the same to the Vaction ot'a weak alkalinesolution, under a snperatmospheric pressure, and atl a temperature of not more than 2120, so as to avoid the formation of steam in the disintegrating-vat, substantially as v herein set ort-h.

2. The within-described apparatus for treating fibrous materials under superatmospheric pressure.

. AUGUST DEININGER.

Witnesses:

FRIED'. HQFFMANN FRIED, J AENISKE.

desire to secure by 

